NUCLEAR REACTOR VIBRATION SURVEILLANCE SYSTEM AND ITS METHOD

• US 20090282920A1
• Filed: 03/23/2009
• Published: 11/19/2009
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Izumi, Mikio, Sato, Mieko, Enomoto, Mitsuhiro, SATO, Michio, Yoda, Masaki, Kuroda, Hidehiko
• Granted Patent: US 8,774,340 B2
• Time in Patent Office: Days
• US Class Current: 73/597
• CPC Class Codes: G01H 1/00 Measuring characteristics of vibrations in solids by using direct conduction to the detector G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/102 one emitter, one receiver
• CPC Class Codes: G01N 2291/2695 Bottles, containers
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/46 by spectral analysis, e.g. Fourier analysis or wavelet analysis spectral signal processing per se G06F17/14
• CPC Class Codes: G21C 17/00 Monitoring; Testing measuring in general G01; Maintaining
• CPC Class Codes: G21C 17/003 Remote inspection of vessels, e.g. pressure vessels
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

A nuclear reactor vibration surveillance system has a first ultrasonic transducer for transmission, an ultrasonic transmitter, a second ultrasonic transducer for reception, an ultrasonic receiver, a signal processor, and a display unit. The first ultrasonic transducer for transmission is arranged on the outer surface of a reactor pressure vessel and is configured to convert a transmission signal into an ultrasonic pulse signal and allow the ultrasonic pulse to be transmitted to a reactor internal component. The second ultrasonic transducer for reception is arranged on the outer surface of the reactor pressure vessel and is configured to receive a reflected ultrasonic pulse reflected by the reactor internal component and convert the received reflected ultrasonic pulse into a reception signal.

Claims

1. A nuclear reactor vibration surveillance system comprising:

a first ultrasonic transducer for transmission which is arranged on the outer surface of a reactor pressure vessel and is configured to convert a transmission signal into an ultrasonic pulse signal and allow the ultrasonic pulse to be transmitted to a reactor internal component;

an ultrasonic transmitter which is electrically connected to the first ultrasonic transducer and is configured to transmit the transmission signal;

a second ultrasonic transducer for reception which is arranged on the outer surface of the reactor pressure vessel and is configured to receive a reflected ultrasonic pulse reflected by the reactor internal component and convert the received reflected ultrasonic pulse into a reception signal;

an ultrasonic receiver which is electrically connected to the second ultrasonic transducer and is configured to receive the reception signal;

a signal processor which is electrically connected to the ultrasonic transmitter and ultrasonic receiver and is configured to input a signal to the ultrasonic transmitter and receive a signal from the ultrasonic receiver so as to apply signal processing to the signal; and

a display unit which is configured to display vibration information of the reactor internal component obtained as a result of the signal processing by the signal processor.

2. The nuclear reactor vibration surveillance system according to claim 1, wherein

the transmission signal is a radio frequency pulse signal.

3. The nuclear reactor vibration surveillance system according to claim 1, wherein

The first ultrasonic transducer can change the incident angle of the ultrasonic pulse.

4. The nuclear reactor vibration surveillance system according to claim 1, wherein

The second ultrasonic transducer can change the reception angle of the ultrasonic pulse.

5. The nuclear reactor vibration surveillance system according to claim 1, wherein

The first ultrasonic transducer can change the incident angle of the ultrasonic pulse, and

The second ultrasonic transducer can change the reception angle of the ultrasonic pulse.

6. The nuclear reactor vibration surveillance system according to claim 1, wherein

the signal processor performs the frequency analysis for the received signal to calculate the original frequency of the reactor internal component which have no extraordinary frequency, and

the display unit displays the temporal change of the difference in frequency.

7. A nuclear reactor vibration surveillance method comprising:

allowing an ultrasonic pulse to be transmitted to a reactor internal component using a first ultrasonic transducer for transmission which is arranged on the outer surface of a reactor pressure vessel;

receiving a reflected ultrasonic pulse reflected by the reactor internal component using a second ultrasonic transducer for reception which is arranged on the outer surface of the reactor pressure vessel; and

applying signal processing to the received reflected ultrasonic pulse signal to analyze the vibration of the reactor internal component.

8. The nuclear reactor vibration surveillance method according to claim 7, comprising:

changing the position of the first ultrasonic transducer and reception angle of the ultrasonic pulse in the second ultrasonic transducer so that the position at which the ultrasonic pulse reflects onto the reactor internal component is moved to change the vibration measurement position.

9. The nuclear reactor vibration surveillance method according to claim 7, comprising:

changing the incident angle of the ultrasonic pulse to be transmitted from the first ultrasonic transducer and position of the second ultrasonic transducer so that the position at which the ultrasonic pulse reflects onto the reactor internal component is moved to change the vibration measurement position.

10. The nuclear reactor vibration surveillance method according to claim 7, comprising:

changing the positions of the first ultrasonic transducer and the second ultrasonic transducer so that the position at which the ultrasonic pulse reflects onto the reactor internal component is moved to change the vibration measurement position.

11. The nuclear reactor vibration surveillance method according to claim 7, comprising:

changing the incident angle of the ultrasonic pulse to be transmitted from the first ultrasonic transducer and reception angle of the ultrasonic pulse in the second ultrasonic transducer so that the position at which the ultrasonic pulse reflects onto the reactor internal component is moved to change the vibration measurement position.